Wireless digital networks, such as networks operating under the current Electrical and Electronics Engineers (IEEE) 802.11 standards, are spreading in their popularity and availability. In a wireless local area network (WLAN) deployment, a number of clients can be connected to the same wireless network via one or more access points. The speed of WLAN has been drastically improved and will likely match the wired speed in the edge networking in the near future. Also, wireless management and security are both in a rapidly growing area. Meanwhile, IEEE 802.11 a/g radios are available as a single chip solution at a cheap cost, which allows most clients to be dual band capable.
The load on a wireless medium is typically handled by one or more radios residing on an access point (AP). Conventionally, APs are designed to use the radios statically. For example, one radio may be assigned to serve as an IEEE 802.11 a radio, whereas another radio may be assigned to serve as an IEEE 802.11 g radio. Thus, to support dual band mode, the AP will need at least two radios to be powered up, which consumes more power than a single radio. On the other hand, it shall be noted that the WLAN chipset supports both IEEE 802.11 a and IEEE 802.11 g radios in a single chip. The chip is usually statically programmed to be supporting either an IEEE 802.11 a or an IEEE 802.11 g radio.
Also, multiplexing operations may overload the radio, and thus causing compromised transmission quality and/or radio performance. In some scenarios, in order to serve the area better, one of the AP's radios needs to be disabled. The AP vendor will need to statically define when programming the WLAN chip whether and which steams should be disabled when deploying the AP, so that the AP can serve its installed area better.
Conventionally, an AP is powered by a Power over Ethernet (PoE) port in compliance with IEEE 802.1 of standard. With the latest technologies, APs are equipped with high capabilities and may require high power from a PoE+ port in compliance with IEEE 802.1 at standard. Nonetheless, using the PoE+ port requires infrastructure changes that may not be desirable to be configured in the AP statically.
Sometimes, a separate AP is dedicated for spectrum monitoring. This approach has the drawback of requiring more APs to be installed. Sometimes, an AP is configured to be running in a hybrid mode that performs both air scanning and air monitoring functions. This approach may compromise the performance in serving clients, because the AP needs to switch off its operating channel (on which the AP's clients are connected) to collect Fast Fourier transform (FFT) samples on other channels and performing other air monitoring functionalities.
In order to provide a secure network environment, an AP needs to perform air scanning periodically to detect rogue APs. Adaptive Radio Management (ARM) is one of major functionality of the AP to switch off the operating channel, to scan other channels, and to collect statistical data, including interference data, etc. The ARM functionality is useful in poor radio frequency (RF) environments with a large number of clients and AP's. On the other hand, when the network load is very high and clients are more active, it can be difficult for the AP to switch off its operating channel to perform ARM functionalities.
Last but not least, currently, the wireless intrusion and protection is usually performed by parsing all incoming packets to an AP. However, the AP may hit its limitations to receive packets if its radios are serving a large number of clients. Moreover, the wireless intrusion and protection may also require the AP to switch off channel to perform scanning on other channels, for example, when an intrusion is detected near the AP's physical location on a different channel. As mentioned above, with a heavy load of clients, the AP may not have the capacity to perform such wireless intrusion and protection functionalities.